Combination check valve and flash arrester



S pt- 20, 1949. w. s. BOEDECKER 7 2,482,457

, COMBINATION CHECK VALVE AND FLASH ARRESTER Filed March 23, 1945 IN VEN TOR.

Patented Sept. 20, 1949 CHECK VALVE AND ARRESTER' COMBINATION FLASHWoodrow S. Boedecker, Chicago, Ill., assignor to The Bastian-BlessingCompany, Chicago, 111.,

a corporation of Illinois Application .March 23, 1945, Serial No.584,332

, This invention relates to a safety device such as a flash arresterused in conjunction, with equipment dispensing acetylene gas or oxygen.

Inhandling acetylene or oxygen the danger of dissociation or back firethrough the system is always present due to the temperament of acetyleneand its high flame propagation and to the.

oxidizing ability of oxygen if there is any trace of a fuel or ferrousmaterial in the line.

In order to prevent any flame or pressure wave from reaching the storagetank in which such gases are stored, flame arresters have been designedwhich either add to the hazard unintentionally by becoming defective inuse and creating a false impression of safety or are inadequate forextreme conditions. Other flash arresters materially retard the flow ofgas under heavy load conditions or, if designed to handle heavy loadconditions, are too bulk to be managed conveniently. a

Not only does the present invention overcome these diificulties but italso checks the pressure wave which very often accelerates the activityof the flame wave. In fact, in some instances if the pressure wave,which precedes the flame wave slightly, can be checked, the flame wavecan be brought under control before any definite hazard is created. Onthe other hand very often the flame wave starts very close to the tankand the interval of time between the pressure wall and the flame wall isso small that there is not enough time to check the pressure wave beforethe flame wave has done a great deal of damage.

One of the objects of the present invention is to control both the flamewave and pressure wave regardless of where the flame originates.

The invention is further characterized by a construction in which apressure wave which has been able to get past the flame arrester can bebrought under control without danger of. the pressure wave generating asecondary dissociation or reaction. 7

These being among the objects of the present invention, other andfurther objects will become apparent from the drawing, the descriptionrelating thereto and the appended claims.

In the drawing: 7

Fig. 1 is a side elevation of a tank and manifold system for use withblowpipes in which the invention is incorporated; a

Fig. 2 is a longitudinal section through the flash arrester assemblyconnected to the outlet'of the cylinders illustrated in Fig. 1;

r Fig. 3is a section taken upon'the line 3-4 in 8 Claims. (01. 48-192)Fig. 4 is a modification of the embodiment nlustrated in Fig. 2, and VFig. '5 is a section taken upon the line 55 in Fig. 4.

Referring to Fig. 1, two high pressure cylinders 30 are shown asprovided with shut-off valves 3| at the top thereof to which areconnected embodiments of the present invention comprising a flasharrester l by means of a coupling 32. The

downstream side of the flash arrester l is connectedby pigtails manifold35.

"At the point where gas is removed from the manifold 35, a T 36 isprovided leading to a container 31. serving as a water seal which insome measure is an additional safety factor between the point of usewhere the gas is used and the manifold. The outlet 40 of the water sealis connected to a two stage pressure reducer M by a coupling 42 and theoutlet of the regulator leads to a point of use such as blowpipesthrough a con: duit 43.

The flash arrester I, as herein shown, comprises a bonnet 2 threaded asat 3 to receive a mating connection. A threaded passage 4 conducts gasin the connector 32 to-a ball check 5 to compress a spring 6 of the ballcheck into a retainer 1 under the effective high pressure of theincoming gas.

Y The retainer 1 is-threaded into place upon the same threadingreceiving the bonnet 2 as at l0 and is provided with passageways 8therethrough to permit the gas admitted through the check valve 5 toflow through the retainer 1 to a cartridge l2 held in place by acircular lip l I. With the cartridge held against a shoulder [3 providedin a housing 9 at the base of a cavity l4.

Upon the cartridge l2 .a second check valve I5 is provided setting upona conical seat [6 formed in the housing 9 as held normally closed by acompression spring I! which is supported in a 33 to shut-01f valves 34in a cavityjl8 upon a second bonnet 26 threaded into the housing9 as at2|. The inner end of the second bonnet 20 and the space around the valveseat I 6 define a valve compartment 22 for the gas admitted thereto uponthe compression of the spring I1 by pressure of the gas exerted on theupstream side of the check valve [5. The valve compartment 22 is incommunication with the pigtail 33 through passages 24 drilled throughthe second bonnet 20.

P ssure exerted upon them by the incoming gas metal, sand or siliconbase or stone core 26 held in place at both ends by retaining screens 21and reinforcing reticulated plates 28 closing the two ends of acylindrical shell 29 forming the side Wall mating with the cavity M.

The shell 29 and reticulated reinforcing end plates rigidify the formcartridge against suddenly applied pressures. The screens 21 preventdirt or other formed material from passing However, since in somerespects it is not possible through the filter or entering thefiltenavhile the core 26 serves to spread out the flow of gas throughsmall interstices to follow route channels which bring the gas intointimate contact with the material both to cool it and retard any suddenor excessive flow.

The porosity of the core 26 may be varied to some degree depending uponthe size of the core and its flow area. A convenient size tohandle is acylindrical form inch long andone inch,

in diameter with the cor'e' made of porous iron ofa density within therange of 2.50 grams] cubic centimeter to 2.85 grams/ cubic centimeter toprovide a flow of acetylene of from 140 cubic feet per hour for the 2.50density to 40.7 cubic reg per hour for the 2.85 density. If greater flowis required, the'diam'eter of the core can be increased,

the densities given or equivalent criteria being otherwise safelycapable of snufiin out flames. when flash-backs occur. Density as.ratedhere is based upon'the factor {7.85 grams/ cubic centimeter asbeing thedensity of a solid body of iron and 250/785 being thepercentage of density of the filter core. When other metals than ironare:

used, the ratio of the density of the sintered core to the density ofthe solid metalis maintained within-the limits rase/7.35 and 2.85/7.85.

In the event of a flash back in the manifold which results either inaflame wave or, a pressure wave moving towards the cylinders 35, thecheck valve'lfi will be the first to be affected. If the wave originatesclose to theche-clevalve, the valve 7 may not close before a substantialamount of pressure enters the cavity hi4. From this cavity itbackfiresthrough the filter but by this time the pressures on both sides of thecheck 7 valve 5 are equalized gradually and the, check. valve has'moretime to closehbeforeany high. pressure is effected thereagainst. Oncethe check.

valvesare closed there is loo opportunity for the flame or pressurewaveto enter the connector 32. Theonly thing thatcan happen is that thesurge. of the gas flowing from the cylinders is suddenly stopped.However, theparts are rnade strong enough to take care not, only .of thepressures present in the cylinder but also of. higherpressures expectedin them.

The filter has the effect upon any backilow of gases of coolingthembelow their ignition point, and also separating them into suchsmallchan nels that any flame presentissnuffed out.

In the embodimentillustrated in Fig., 4 thecheck valve i5 is bypassedby.t wo smallpassage It has been found that this slight byways it-. Ipassing with very small passages such .as are proided by a GOto 7b drillhas theadyantage in.

handling oxygen and "acetylene of relieving any dangerous shockviaves'wmch' might have a shatmaterially the passage of flame as well aspressures in event the flash arrester is used with -acetyleneinstallations. Having thus described the apparatus and the embodimentsof the invention it will be apparent from the description how theobjects and processes ot the invention are accomplished.

to account fully for the improved results which are obtained by theinvention, it should be understood that any attempt to analyze thetheory which is believed to be responsible for these resuits is'tobeconstrued not as defining a mode of operation but merely as a,possibleexplanatiori of certain physical and metallurgical phenomenawhich havebeen observed.

"Consequently, although certain preferred embodiments of the inventionhave been shown and described therein, it will be apparent. to, thoseskilled in the art that various uses, modifications and changes can bemade without departingfrom the spirit and substance of the invention,the scope of which is icommensuratewith the appended claims.

What is claimed is:

V 1 A deviceoi the class described comprising a housing havingapassagefor normal movement of gaslunder pressure therethrough inopennestion, a porous cartridge in saidpassage said cartridge being.formed of sintered powderedlmetal having a density such that the ratioof fluid den- .& sity to the density of solidmetal falls within thelimits 2 50/1535 and 2.85/7.85, and aback flow normallyclosed checkvalvein said passagupon the downstream side of said cartridge to protectit initially against Wave shock.

2. A device of the class described comprising a housing having a passagetherethroughthreaded at both. ends, a porous sintered metalcartridge insaid passage. approximately one inch in diameter tion, said spring beingreceived in said recess, and

closuremeans'fcr saidone of the openings having a seat cooperating withsaid check valve member.

3. A flash arrester for use between a highpressure gas cylinder and amanifold comprising a housingha'ving a passage therethrough, a porousmaterial disposed in said passage whose porosity is minute enough tosnuff flame from highly cornbustible gases passingtherethrough,acheclgvalve received in .saidpassagef or obstructing theback flow. of gas, 'andbleeder means for by-passing the check valve fromone side thereoi to theroth er includinga blceder passagethrough saidhousin of, size. withina range of 60 to drill size.

4. A device of the class.. desc ri bed comprising a ho usi g. having. apassage therethrough. divided by an integral flangedefining a 'valveseat and terminated in enlarged threaded openings, a porous cartridgereceived in one of said openings, a retainer holding said cartridge inplace, a pair of closures, one threaded into each of said openings, acheck valve member cooperating with said valve seat and received withinone of said closures, a second check valve member cooperating with avalve seat on the other of said closures, and means includingpassageways through said closures for connecting the housing to a gascylinder and a manifold. I

5. A device of the class described comprising a housing having a passagetherethrough threaded and enlarged at one end to define a cavity andthreaded and shouldered at the other end to present a valve seat, aporous cartridge in said cavity,

means for holding the cartridge in place threaded 7 into said one end,and a check valve disposed into the other end to cooperate with saidvalve seat to obstruct flow of gas through said cartridge except in onedirection, means for by-passing the valve seat including a bleed passageless than .05 of an inch in diameter, said bleed passage extending froma point on one side of said valve seat to a point on the other sidethereof.

6. A device of the class described comprising a housing having a passagetherethrough threaded and enlarged at one end to define a cavity andthreaded and shouldered at the other end to present a valve seat, aporous cartridge in said cavity, means threaded into said one end forholding the cartridge in place including a perforate retainer and aclosure having a second valve seat thereon, a check valve membercooperating with said second valve seat, and another check valve memberthreaded into the other end to cooperate with said first mentioned valveseat, said check valves cooperating to obstruct flow of gas through saidcartridge except in one direction.

7. A device of the classdescribed for use in a high pressure connectionbetween a high pressure cylinder and a manifold ahead of a pressurereducer, comprising a housing having a passage therethrough threaded andenlarged at one end to define a cavity upon one side of a Wall andthreaded and shouldered upon thesother side of the wall to provide avalve seat surrounding a passage through the wall, a perforate elementsupported in the cavity in spaced relation to the Wall, a porouscartridge of sintered metal in said cavity resting against said element,means threaded into said one end for holding the cartridge in placeincluding a perforate retainer and an adaptor having a check valvetherein, a second check valve supported in the other end to cooperatewith said valve seat, said check valves cooperating to obstruct the flowof gases therethrough except in one direction, and means for by-passingsaid valve seat comprising a bleed passage through said wall less than.05 of an inch indiameter.

8. A filter for arresting flame comprising a sintered porous metal corehaving a density such that the ratio of said density to the density ofsolid metal is within the limits 2.50/7.85 and 2.85/7.85, dirt screensat both ends, reinforcing reticulated plates holding the screens inplace, and means for sealing the sides of the core from dirt.

WOODROW S. BOEDECKER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,497,197 Schroder June 10, 19241,962,074 Hausmeister June 5, 1934 2,157,596 Davis May 9, 1939 FOREIGNPATENTS Number Country Date 23,855 Great Britain Aug. 17, 1911 744,473France Jan. 26, 1933

